Porsche liked to talk about the V10 from the Carerra GT coming from a cancelled endurance racing program, but it has roots even deeper than that.

What appears in the Carerra GT as a 5.7 liter V10 started life in 1992 as a 3.5 liter V10 intended for the Footwork F1 team. That V10 was to replace the underperforming V12 Porsche had made for Footwork before. The whole project got cancelled.

In 1999 the engine was stroked and slightly bored up to 5.0 and 5.5 liters for the also-cancelled 9R3 LMP1 program.

The 5.5 liter version got brought onto the road in 2004, sorta-kinda making the run between the two most prestigious race series there are.

There's only one other engine in a road car that began as a race engine in both F1 and endurance racing: the Ferrari Dino V6. Can you think of any?